In power electronics very often semiconductor chips with vertical transistors like, for example, IGBT (Insulated Gate Bipolar Transistors) are used or, in general, transistors in which at least one electrical contact pad is arranged on a first main face of the semiconductor chip and at least one other electrical contact pad is arranged on a second main face opposite to the first main face. Several ones of these semiconductor power transistors can be connected to form particular power switches, power modules or power systems. In these power applications one important aspect is a low ON-resistance of the power device which means that firstly the vertical semiconductor dies should be fabricated with a low thickness and secondly, in case of interconnected power semiconductor chips, a direct interconnect between the drain pad of one chip to the source pad of a second chip should be achieved in order to have a very short connection and therefore a low resistivity and low parasitic effects.